Fountain pen



June 23, 1953 D, KAHN Erm..

FOUNTAIN PEN Filed oct. 11. 1946 N SS Patented June 23, 1953 UNITEDSTATES PATENToFFmE YDNTAIN vN l David Kahn, Englewood, and Karl Weisser,Qresskill, N. -J-., assiznors to David Kami,V Inc., 4North Bergen, N.J., a. corporation of New J ersey Ammoa'tion ootobor 11, 194'6, soi-iaiNo. natifs (etica-46) Claims. 1

The presentv invention relates to a writing in*- strument. Moreparticularly, the present invention relates to a writing instrument ofthe type utilizing a freely rotating ball as the writing tip andprovided With a suitable reservoir for supplyi ing a thick, viscousWriting fluid to the vball point.

Writing instruments ofthi'S 'type 'possess Ymany' advantages over 'theordinary and convention-al writing nib type of fountain peni Arelatively small amount of viscous 'uid is fed 'to 'the parer by therotating ball and Consequently a single charge of writing fluid a pen ofthis char-- acter will last for a substantial period of time.

The thin layer of viscous fluid which is deposited y upon the Writingsurface needs no blotting lsince by its very nature it is substantiallydry upon deposition. In addition, the freely rotating ball will make alegible lineoon relatively rough sur'- faces, such as cloth and othermaterials, which the conventional writing nib ,is incapable of freelytraversing. v

Even with the advantages hereinbefore set forth, however, Vwritinginstruments ofthis type are not always satisfactory, since it is,diflicult'to supply a continuous smooth feed of this material to thewriting tip. The thick fluid can not bek easily sucked into thereservoir in the manner in which Writing fluid or ink is sucked into thereservoir by the sac of a conventional pen. In fountain pens of thischaracter, therefore, it has been customary to charge a reservoir ofsome type at the factory and supply the pen together with the Writingfluid to the user thereof. It has also been difficult to satisfactorilyfeed the fluid to the writing point and for this Areason fountain pensof this type now in use have utilized Weights or pistons for feedingfluid to the Writing tip. Another type of pen having a writing ball isprovided with a reservoir which consists of a rela= tively large numberof connected -small conduits capable of feeding 'uidby capillary actiontothe writing ball. In this type of pen, the amount of fluid which canbe retained in the reservoir of the pen is limited by the small size ofthe capillary, conduits utilized. In the type of pen which embodies aweight or a 'piston or equivalent means for exertinga'pressure'onthe'thick fluid to facili-Y tate the feed thereof tothewriting point, it has been difficult to 'prevent leakage of the fluidpast the piston. As may be understood, the VApiston or Weight shouldhave a free yrnoven'ient within the cylinder constituting the Vreservoirand with such movement it is almost impossible toprevent leak,- age offluid lpast lthe piston or weight.

It is one of the objects of the present invent-'rtion, therefore, t'o.provide a novel writing instru; ment preferably of the type employing afreely rotating `ball as the writing point, said instru'- m'ent beingprovided 'with a reservoir capable 'of retaining a relatively largeamount of thick viscous `writing ilui'd and of feeding said iluidsmoothly under substantially uniform pressure to the writing tip. l n

A second object of the present invention is to provide in a writinginstrument of the character described, fa vnovel 'reservoir including aresilient, preferably rubber, sac for exerting a constant pressure onthe Writing fluid, said reservoir having a large capacity for writingfluid which lis not determined by the capacity 'of 'the rubber sac.

A third object of 'the present invention is to provide a Writinginstrument of the character described a relatively nlarge space actingas a reservoir for a thick Aviscous Writing fluid, said space beingbounded rby non-yielding walls capa; ble of sustaining substantialpressure and a means, preferably a rubber sac, for exerting a substantial pressure on `the writing fluid in 4said reser;

voir.

A fourth object ofthe present invention is provide in a writinginstrument of the ltype chariacterized by the provision of a freelyrotating ball point, a reservoir for writing fluid including a rubbersac disposed within the reservoir and positioned lsubstalitially on thelongitudinal axis thereof for exerting pressure on the fluid in thereservoir. w l Y A- fifth object of the present invention is to providea writing instrument of the characterr Vwithin the reservoir, which hascompressed `said sac so that it will occupy a lesser volume that of thereservoir when the reservoir is filled. other objects and `suivantago/sof the present invention win beoomeapparont from the sub= sequentdescrbtiol fid figures `of .the drawings, wherein: f o' I' Figure 1 isrva section of the writing instrument with the up in non-assembledriationland the Sao donated ready Vfor `meaning operation;k

Fig. y2 is a longiouumm section through the writing instrument of thepresent invention;

Figs. ,315s a section simuarto Fis.. 2 with the sac expanded as afterthewriting fluid has been ex'- Fig. 4 is a transverse section taken onthe line 4-4 of Fig. 2;

Fig. 5 is an enlarged longitudinal section of a modification of thepresent invention;

Fig. 6 is a section taken on the line 6 6 of Fig. 5; and

Fig. 7 is a detail partly in section showing the construction of the endof the sleeve and sac.

Referring to the figures of the drawing and particularly Figure 2, awriting instrument in accordance with the present invention is shown,including a barrel indicated in general at I0. Fitted into the forwardend of the barrel is a pen section I I provided with a rearward reducedportion I2 which is frictionally fitted within the lower end of thebarrel proper. Preferably both the barrel and the pen section are formedfrom a suitable plastic material such as Celluloid or hard rubber, orany of the other plasti-cs conventionally utilized for this purpose inthe art. The lower end of the pen section has fitted therewith a tipmember I3, preferably formed from a suitable metal material. The tipmember I3 is provided with a reduced portion I4 at its upper end and aseat I5 at its lower end which is adapted to retain a small, freelyrotatable writing ball I6. Preferably the seat I5 is bent over the endof the writing ball sufliciently to retain the same therewithin and thewriting ball is fitted into said seat in such manner as to be freelyrotatable.

The seat I5 communicates at its upper end with a relatively smallchannel I1, which in turn communicates with a relatively larger channelor bore I8, both of these channels or bores being adapted to convey arelatively thick writing fluid to the seat I5 and the ball IS.

The pen section is provided with a bore I9 which is adapted to receive areservoir retaining and feed member 2l), the forward or lower end of thefed member being interposed between the reduced portion I4 of the tipand the walls of the bore I9 of the pen section II. At its rearward orupper end, the portion 20 is provided with an annular shoulder orvprojection which is seated on the end of the reduced portion I2 of thepen section II, the shoulder being indicated at 2|. An extended portion22 of the member 20 furnishes a seat for a reservoir proper which isindicated at 23. The reservoir 23 is preferably made of metal or plasticor other material capable of withstanding a substantial amount ofpressure. Fitted within the upper end of the reservoir 23 in such amanner as to retain a sac 24 therein is a plug member 25 having anorifice 26 extending axially therethrough. The orifice 26 is preferablythreaded to receive a screw for a purpose to be hereinafter described.

The upper end of the barrel I0 is provided with a small opening or airvent 21 and with a loosely threaded cap or plug 28 which is adapted toclose the upper end thereof. The sac 24 is preferably formed fromresilient material such as rubber or any of the artificial elastomers orartificial rubbers known in the art, i. e., such materials as neoprene,butyl rubber or any other material having rubber-like characteristicsand substantial resilience and recovery properties.

At the lower end of the sac 24 about a reduced portion or extension 29thereof, there is provided a metallic spider 30. As shown in Figs. 3 and4 this spider 30 is provided with arms 3|, 32 and 33 which radiate froman annular central portion 34 thereof which is fitted on the projection29 of the sac and serves to center the sac within the reservoir 23. Asshown in Fig. 2, when the reservoir is filled with ink, the sac isaxially compressed upon itself. The spider 30 which is fixed to the end29 of the sac 24 has a sliding fit with the inner wall of the reservoir23. As shown in Fig. 3, when the sac is expanded, the spider is drawnupwardly within the barrel to a slight extent.

The spider serves to not only centralize the sac Within the reservoir,but also to maintain the closed end of the sac compressed and therebyenables the sac to exert a more uniform even pressure on the ink. If thespider or some equivalent means are not used, the closed end of the sacbeing of a heavier rubber than the mid portion or open end of the sactends to expand first when driving the ink out of the barrel, andconsequently ink may be trapped by the sac and not fed to the point.

It is desired to point out that by providing means to partially compressthe closed end of the sac 24, it is made certain that the expansion ofthe sac is initiated near and adjacent the open end of the sac insteadof the closed end, and this would occur in the absence of such meanswith the resulting entrapment of the writing fluid and prevent the useof the latter for writing purposes. That is, the life of the writinginstrument would be shortened.

It is preferred that the means foi compressing the lower end of the sac24 also, as stated, function to centralize the sac 24 in the reservoir23 as this insures that the writing iiuid is substantially evenlydistributed around the sac 24 and evenly dispelled from the reservoir 23to the channels I8 and Il and the ball I6. However, in one form of theinvention hereinafter described, centralization may be dispensed with.

Ink is charged into the pen of the present invention in the followingmanner. Referring to Fig. 1, prior to the charging operation the screw26a is removed, and the tip I3 is also removed. Thereafter the sac 24 isdeflated to the position shown in Fig. l by first applying air pressurefrom any desired source. Any suitable pressure may be employed, as forexample, 2 to 5 lbs. per sq. in. This pressure acting on the sac 24deates the same. During the period of deflation the screw 26a is removedfrom the plug 25. After deflation the screw 25a is placed into the plug25, and this insures that the sac 24 is prevented from infiating underatmospheric pressure. The reservoir 23 is then ready to be filled withwriting ink, the latter being fed from an ink feeding device not shown,any suitable pressure being employed, the reservoir 23 being completelyfilled to its brim with the writing fiuid. From the above it is clearthat the sac 24 is held in its deflated position both prior to thefeeding of the writing fluid and after the feeding of the writing fluidto the reservoir 23. This prevents the sac 24 from forcing the ink outof the feed member 20 prior to the assembly of the tip I3 therewith.Preferably the dense writing uid is fed around the sac and into thereservoir under pressure and in such a manner as to avoid entrapment ofair therein. When the member I4 of the tip I3 is inserted in the feedmember 20 after filling to the brim of the open end of the feed member20, sufficient iiuid is displaced to ll the channels I8 and I'I of thetip with the writing fluid. Thereafter, the screw 26a is removed, andthe pressure of the sac 24 against the writing iiuid in the reservoir 23serves to feed ink upon rotation of the ball I6.

In the modification of the device shown in Figs. 5 and 6. a sac is shownwhich is provided with a small clip 39 about the closed end thereof. Thefunction of this small clip 'which has fa 'general U-shape is to preventthe sac from expanding from the closed end first.

In Fig. '7 there is shown an enlarged detail of the end of the sleeve 23and the modifledplug 35 inserted therein. As shown the end of they'sleeve 23 is swaged inwardly as indicated at X36. This serves tocompress the sac between the plug 35 and the sleeve 23, this compressionbeing indicated by the reduced portion 31 of the sac. In assembling thesac and sleeve 23 the sac Iis i'irst placed over the reduced portion ofthe plug 35, and then the sleeve 23 is slipped over the sac and plug.Thereafter, the end of the sleeve 23 is swaged against the plug tocompress the sac.

Having described our invention, what we claim l. In a writing instrumenthaving a writing point and a feed channel communicating therewith, areservoir for writing fluid comprising an elongated writing chamber forsaid writing fluid opening into said feed channel, an elastic sac memberwithin said chamber having a closed end and its upper open end and itsinterior open to the atmosphere, and exerting a constant pressure onsaid fluid to force the fluid into said feed channel, a spider about thelower closed end of said sac member having an annular central portionabout said sac member and a plurality of arms extending from saidcentral portion into sliding contact with the walls of the elongatedchamber so as to centralize said sac member within said chamber.

2. In a fountain pen including a point, a reservoir comprising asleeve-like member for holding a writing uid, a ilexible s ac withinsaid sleevelike member having a closed end and its interior open to theatmosphere and normally pressing against said fluid to expel the same,and having an open end within the upper end of said sleevelike member,means to receive and hold the upper end of said sac against the upperend of said sleeve-like member, and mechanical compressing means aboutthe closed end of the elastic sac member compressing said closed end andpreventing premature expansion thereof.

3. In a writing instrument having a writing point and a feed channelcommunicating therewith, a reservoir for writing fluid comprising anelongated chamber for said writing fluid opening into said feed channel,an elastic sac member within said chamber having a closed end and itsinterior open to the atmosphere, said sac exerting a constant pressureon said fluid to force the fluid into said feed channel, means to retainthe upper end of said sac in position in said chamber, and mechanicalcompressing means about the closed end of said elastic sac compressingsaid closed end and preventing premature expansion thereof.

4. In a writing instrument having a writing point and a feed channelcommunicating therewith, a reservoir for Writing fluid comprising anelongated chamber for said writing fluid opening into said feed channel,an elastic sac member within said chamber having a closed end and itsinterior open to the atmosphere, said sac exerting a constant pressureon said fluid to force the fluid into said feed channel, means to retainthe upper end of said sac in position in said chamber, and mechanicalcompressing means cooperating with said sac member compressing saidclosed end and insuring expansion of said sac member constant pressureon said fluid to force the fluid into` said feed channel, means toretain the upper end of saidsaoinposition in said chamber, andmechanical compressing means about the closed end of the elastic sacmember compressing said closedV end and' preventing premature expansionof said closed end, said means being in sliding l contact with the wallof the reservoir.

6. In a Writing instrument having a writing point and a feed channelcommunicating therewith, a reservoir for writing fluid comprising anelongated chamber for said writing fluid opening into said feed channel,an elastic sac member within said chamber having a closed end and itsinterior open to the atmosphere and exerting a constant pressure on saidfluid to force the fluid into said feed channel, means to retain theupper endof said sac in position in said chamber, and mechanicalcompressing means cooperating with said sac member and compressing saidclosed end and insuring expansion of said sac member at a point spacedfrom the closed end thereof prior to the expansion of the closed end,said means being in sliding contact with the wall of the reservoir.

7. In a writing instrument having a writing point and a feed channelcommunicating therewith, a reservoir for writing fluid comprising anelongated Writing chamberv for said Writing fluid opening into said feedchannel, an elastic sac member within said chamber having a closed endand its upper open end and its interior open to the atmosphere, andexerting a constant pressure on said iiuid to force the fluid into saidfeed channel, an annular member about the lower closed end of the sacand compressing said sac at the closed end, and means associated withsaid annular member for centralizing said sac within the Writingchamber.

8. The writing instrument defined in claim 7 in which the annular memberis in sliding contact with the wall of the reservoir.

9. In a fountain pen including a point, a reservoir comprising asleeve-like member for holding a writing fluid, a flexible sac withinsaid sleeve having a closed end and its interior open to the atmosphereand normally pressing against said fluid to expel the same, and havingan open end within the upper end of said sleeve, means to receive andhold the upper end of said sac against the upper end' of said sleeve,mechanical compressing means about the closed end of the elastic sacmember compressing said closed end and preventing premature expansionthereof, and means associated with said compressing means forcentralizing said sac within the reservoir.

10. In a writing instrument having a writing point and a feed channelcommunicating therewith, a reservoir for writing fluid comprising anelongated chamber for said writing fluid opening into said feed channel,an elastic sac member within said chamber having a closed end and itsinterior open to the atmosphere, said sac exerting a constant pressureon said fluid to force the fluid into said feed channel, means .toretain the upper end of said sac in position in said chamber,

mechanical compressing means cooperating with said sac membercompressing said closed end and insuring expansion of said sac member ata. point spaced from the closed end thereof prior to the expansion ofthe closed'end, and means associated with said compressing means forcentraiizing said sac within the reservoir.

DAVID KAHN.

KARL WEISSER.

Name Date Fisk Jan. 16, 1900 Number Number 1 807,280 1,177,631 2,408,2565 2,425,198 2,427,068 2,432,061 2,444,003 2,444,004

Number 8 Name Date Kegrize Dec. 12, 1905 A Johnson Apr. 4, 1916 FlormanApr. 5, 1946 Moore Aug. 5, 1947 Randolph Sept. 9, 1947 Chesler Dec. 2,1947 Chesier June 22, 1948 Chesler June 22, 1948 FOREIGN PATENTS CountryDate Great Britain 1937

